Polyolefin nanocomposite compositions

ABSTRACT

A nanocomposite composition having improved mechanical properties containing, A. about 5 to about 20 wt % of a compatibilizing dispersant chosen from an olefin polymer peroxide, an ionomer of an olefin polymer peroxide, a grafted olefin polymer peroxide, an mixtures thereof; B. about 1 to about 15 wt % of a smectite clay; and C. about 65 to about 94 wt % of an olefin polymer material; wherein the sum of components A+B+C is equal to 100 wt %.

The present invention relates to polyolefin nanocomposite compositionscontaining smectite clays, polymeric peroxide compatibilizingdispersants, and olefin polymer material, and articles made therefrom.

Layered clay minerals such as smectite clays are composed of coplanar,closely-spaced silicate layers, and are quite polar. It is known thatsuch clays, e.g., sodium and calcium montmorillonite, can be treatedwith various types of swelling agents such as organic ammonium ions, tointercalate the swelling agent molecules between adjacent, planarsilicate layers, thereby substantially increasing the interlayerspacing. In such a condition, substantially less shear is required toseparate the platelet layers from each other. When sufficient shear isapplied to the intercalated particles to overcome the forces holding thelayers together, de-lamination of the clay particles occurs, anddiminuted clay particles are obtained. Such particles are referred to asexfoliated clay particles. When the exfoliated clay particles aredispersed in the matrices of a polymer material, the resultingcomposition is referred to as a nanocomposite composition. Suchcompositions have been found to substantially improve one or moreproperties of the polymer, such as modulus and/or high temperaturecharacteristics. In polymer nanocomposite compositions, the inorganic,polar clay is incompatible with the organic, non-polar polymer. There isthus an incentive to enhance the compatibility and dispersion of theinorganic clay within the polymer matrix, and to maintain thethermodynamic stability of such a dispersion, once established, in orderto take advantage of an enhancement in mechanical properties above andbeyond what is normally realized by conventional filled polymers.Further, it is known that the nucleation of olefin polymer material alsoenhances its mechanical properties. There is therefore, also anincentive to improve the nucleation of the olefin polymer matrix withinwhich the clay is dispersed.

It is known that polyolefin nanocomposite compositions generally makeuse of materials such as maleic anhydride-grafted polyolefins tocompatibilize and disperse smectite clay in the polymer matrix. Forexample, U.S. Pat. No. 6,423,768 discloses polymer-organoclaycompositions that include compatibilizers such as dicarboxylic acids,tricarboxylic acids and cyclic carboxylic acid anhydrides. U.S. Pat. No.6,407,155 discloses nanocomposite compositions containing couplingagents such as silanes, titanates, aluminates, zirconates; and an omniumion spacing/compatibilizing agent. U.S. Pat. No. 6,451,897 disclosesnanocomposite compositions containing a graft copolymer of a propylenepolymer material and a smectite-type clay that has been treated with aswelling agent. However, there continues to be a need forcompatibilizing dispersants that enhance the mechanical properties ofolefin polymer nanocomposite compositions through improvedcompatibilization and dispersion of the clay within the olefin polymermatrix, and improvement in the nucleation of the olefin polymermaterial.

It has unexpectedly been found that the addition of specific polymericperoxide compatibilizing dispersants improve the mechanical propertiesof nanocomposite compositions, and enhance the nucleation of the olefinpolymer material.

The present invention relates to polyolefin nanocomposite compositionscomprising:

-   -   A. about 5 to about 20 wt % of a compatibilizing dispersant        chosen from an olefin polymer peroxide, an ionomer of an olefin        polymer peroxide, a grafted olefin polymer peroxide, and        mixtures thereof;    -   B. about 1 to about 15 wt % of a smectite clay; and    -   C. about 65 to about 94 wt % of an olefin polymer material.

FIG. 1 is a transmitted light image of a 97/3 blend of a propylenehomopolymer and montmorillonite clay, shown at a 290× magnification.

FIG. 2 is a transmitted light image of an 87/10/3 blend of a propylenehomopolymer, polymeric peroxide and montmorillonite clay, according tothe present invention, shown at a 290× magnification.

FIG. 3 is a cross-polarized light image of a 97/3 blend of a propylenehomopolymer and montmorillonite clay, shown at a 290× magnification.

FIG. 4 is a cross-polarized light image of an 87/10/3 blend of apropylene homopolymer, polymeric peroxide and montmorillonite clay,according to the present invention, shown at a 290× magnification.

FIG. 5 is a DSC cooling scan for: a 97/3 blend of a propylenehomopolymer and montmorillonite clay; an 87/10/3 blend of a propylenehomopolymer, polymeric peroxide and montmorillonite clay, according tothe present invention; an 87/5/5/3 blend of a propylene homopolymer, apolymeric peroxide, a maleated propylene polymer, and montmorilloniteclay, shown at a 290× magnification.

Smectite clays are layered clay minerals composed of silicate layerswith a thickness on a nanometer scale, having different properties thanthe kaolin clays conventionally used as fillers in polymer materials.Suitable smectite clay in the compositions of the invention include, forexample, montmorillonite, nontronite, beidellite, volkonskoite,hectorite, saponite, sauconite, sobockite, stevensite and svinfordite,where the space between silicate layers is typically about 17 to about36 angstroms, measured by small angle X-ray scattering. Montmorilloniteis preferred.

The smectite clay mineral can be untreated, or it can be modified with aswelling agent to increase the interlayer spacing. The expansion of theinterlayer distance of the layered silicate facilitates theintercalation of the clay with other materials. The organic swellingagent used to treat the clay is typically a quaternary ammoniumcompound, excluding pyridinium ion, such as, for example, poly(propyleneglycol)bis(2-aminopropyl ether), poly(vinylpyrrolidone), dodecylaminehydrochloride, octadecylamine hydrochloride, dodecylpyrrolidone, ormixtures thereof. The clay can be swelled with water before introducingthe quaternary ammonium ion.

The smectite clay may be ground to a desired particle size range priorto mixing with the olefin polymer and polymeric peroxide. The smectiteclays are present in an amount from about 1 to about 15 wt % based onthe total weight of the composition. Preferably, the smectite clays arepresent in an amount from about 2 to about 10 wt %, more preferably inan amount from about 2 to about 5 wt %.

Polymer materials suitable as the starting material for making thepolymeric peroxides of the invention, and for the olefin polymermaterial that is combined with the smectite clay and compatibilizingdispersants of the invention, include propylene polymer materials,ethylene polymer materials, butene-1 polymer materials, and mixturesthereof.

When a propylene polymer material is used as the olefin polymer materialor as the starting material for the polymeric peroxide, the propylenepolymer material can be:

-   -   (A) a homopolymer of propylene having an isotactic index greater        than about 80%, preferably about 90% to about 99.5%;    -   (B) a random copolymer of propylene and an olefin chosen from        ethylene and C₄-C₁₀ α-olefins, containing about 1 to about 30 wt        % of said olefin, preferably about 1 to 20 wt %, and having an        isotactic index greater than about 60%, preferably greater than        about 70%;    -   (C) a random terpolymer of propylene and two olefins chosen from        ethylene and C₄-C₈ α-olefins, containing about 1 to about 30 wt        % of said olefins, preferably about 1 to 20 wt %, and having an        isotactic index greater than about 60%, preferably greater than        about 70%;    -   (D) an olefin polymer composition comprising:        -   (i) about 10 parts to about 60 parts by weight, preferably            about 15 parts to about 55 parts, of a propylene homopolymer            having an isotactic index of at least about 80%, preferably            about 90 to about 99.5%, or a crystalline copolymer chosen            from (a) propylene and ethylene, (b) propylene, ethylene and            a C₄-C₈ α-olefin, and (c) propylene and a C₄-C₈ α-olefin,            the copolymer having a propylene content of more than about            85% by weight, preferably about 90% to about 99%, and an            isotactic index greater than about 60%;        -   (ii) about 3 parts to about 25 parts by weight, preferably            about 5 parts to about 20 parts, of a copolymer of ethylene            and propylene or a C₄-C₈ α-olefin that is insoluble in            xylene at ambient temperature; and        -   (iii) about 10 parts to about 80 parts by weight, preferably            about 15 parts to about 65 parts, of an elastomeric            copolymer chosen from (a) ethylene and propylene, (b)            ethylene, propylene, and a C₄-C₈ α-olefin, and (c) ethylene            and a C₄-C₈ α-olefin, the copolymer optionally containing            about 0.5% to about 10% by weight of a diene, and containing            less than about 70% by weight, preferably about 10% to about            60%, most preferably about 12% to about 55%, of ethylene and            being soluble in xylene at ambient temperature and having an            intrinsic viscosity of about 1.5 to about 4.0 dl/g;            the total of (ii) and (iii), based on the total olefin            polymer composition being from about 50% to about 90%, and            the weight ratio of (ii)/(iii) being less than about 0.4,            preferably about 0.1 to about 0.3, wherein the composition            is prepared by polymerization in at least two stages;    -   (E) a thermoplastic olefin comprising:        -   (i) about 10% to about 60%, preferably about 20% to about            50%, of a propylene homopolymer having an isotactic index of            at least about 80%, preferably about 90 to about 99.5% or a            crystalline copolymer chosen from (a) ethylene and            propylene, (b) ethylene, propylene and a C₄-C₈ x-olefin,            and (c) ethylene and a C₄-C₈ α-olefin, the copolymer having            a propylene content greater than about 85% and an isotactic            index of greater than about 60%;        -   (ii) about 20% to about 60%, preferably about 30% to about            50%, of an amorphous copolymer chosen from (a) ethylene and            propylene, (b) ethylene, propylene, and a C₄-C₈ α-olefin,            and (c) ethylene and an α-olefin, the copolymer optionally            containing from about 0.5% to about 10% of a diene, and            containing less than about 70% ethylene and being soluble in            xylene at ambient temperature; and        -   (iii) about 3% to about 40%, preferably about 10% to about            20%, of a copolymer of ethylene and propylene or an α-olefin            that is insoluble in xylene at ambient temperature; and    -   (F) mixtures thereof.

When an ethylene polymer material is used as the olefin polymer materialor as the starting material for the polymeric peroxide, the ethylenepolymer material is chosen from (a) homopolymers of ethylene, (b) randomcopolymers of ethylene and an alpha-olefin chosen from C₃₋₁₀alpha-olefins, (c) random terpolymers of ethylene and saidalpha-olefins, and (d) mixtures thereof. The C₃₋₁₀ alpha-olefins includethe linear and branched alpha-olefins such as, for example, propylene,1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene,3,4-dimethyl-1-butene, 1-heptene, 3-methyl-1-hexene, 1-octene and thelike.

When the ethylene polymer is an ethylene homopolymer, it typically has adensity of about 0.89 g/cm³ or greater, and when the ethylene polymer isan ethylene copolymer with a C₃₋₁₀ alpha-olefin, it typically has adensity of about 0.91 g/cm³ to less than about 0.94 g/cm³. Suitableethylene copolymers include ethylene/butene-1, ethylene/hexene-1,ethylene/octene-1 and ethylene/4-methyl-1-pentene. The ethylenecopolymer can be a high density ethylene copolymer or a short chainbranched linear low density ethylene copolymer (LLDPE), and the ethylenehomopolymer can be a high density polyethylene (HDPE) or a low densitypolyethylene (LDPE). Typically the LLDPE and LDPE have densities ofabout 0.910 g/cm³ to less than about 0.940 g/cm³ and the HDPE and highdensity ethylene copolymer have densities of greater than about 0.940g/cm³, usually about 0.95 g/cm³ or greater. In general, ethylene polymermaterials having a density from about 0.89 to about 0.97 g/cm³ aresuitable for use in the practice of this invention. Preferably, theethylene polymers are LLDPE and HDPE having a density from about 0.89 toabout 0.97 g/cm³.

When a butene-1 polymer material is used as the olefin polymer materialor as the starting material for the polymeric peroxide, the butene-1polymer material is chosen from a normally solid, high molecular weight,predominantly crystalline butene-1 polymer material chosen from:

-   (1) a homopolymer of butene-1;-   (2) a copolymer or terpolymer of butene-1 with a non-butene    alpha-olefin comonomer content of about 1 to about 15 mole %,    preferably about 1 to about 10 mole %; and-   (3) mixtures thereof.

Typically the non-butene alpha-olefin comonomer is ethylene, propylene,a C₅₋₈ alpha-olefin or mixtures thereof.

The useful polybutene-1 homo or copolymers can be isotactic orsyndiotactic and have a melt flow rate (MFR) from about 0.5 to about150, preferably from about 0.5 to about 100, and most preferably fromabout 0.5 to about 75 g/10 min.

These poly-1-butene polymers, their methods of preparation, and theirproperties are known in the art. An exemplary reference containingadditional information on polybutylene-1 is U.S. Pat. No. 4,960,820.

Suitable polybutene-1 polymers can be obtained, for example, byZiegler-Natta low-pressure polymerization of butene-1, e.g. bypolymerizing butene-1 with catalysts of TiCl₃ or TiCl₃—AlCl₃ andAl(C₂H₅)₂Cl at temperatures of about 10 to about 100° C., preferablyabout 20 to about 40° C., e.g., according to the process described inDE-A-1,570,353. It can also be obtained, for example, by usingTiCl₄—MgCl₂ catalysts. High melt indices are obtainable by furtherprocessing of the polymer by peroxide cracking or visbreaking, thermaltreatment or irradiation to induce chain scissions leading to a higherMFR material.

Preferably, the polybutene-1 contains up to about 15 mole % ofcopolymerized ethylene or propylene, but more preferably it is ahomopolymer, for example, Polybutene PB0300 homopolymer marketed byBasell USA Inc. This polymer is a homopolymer with a melt flow of 11g/10 min. at 230° C. and 2.16 kg and a weight average molecular weightof 270,000 dalton.

Preferably, the polybutene-1 homopolymer has a crystallinity of at leastabout 55% by weight measured with wide-angle X-ray diffraction after 7days. Typically the crystallinity is less than about 70%, preferablyless than about 60%.

Preferably, the olefin polymer material is a propylene polymer material.More preferably, the olefin polymer material is a crystallinehomopolymer of propylene having an isotactic index greater than about80%, preferably about 90% to about 99.5%.

The olefin polymer material is present in an amount from about 65 toabout 94 wt % based on the total weight of the composition. Preferably,the olefin polymer material is present in an amount from about 75 toabout 91 wt %, more preferably in an amount from about 83 to about 90 wt%.

The compatibilizing dispersants are chosen from polymeric peroxides,ionomers of a polymer peroxide, grafted polymeric peroxides, andmixtures thereof. The polymeric peroxides contain greater than 1 mmoltotal peroxide per kilogram of the polymeric peroxide. Preferably, thepolymeric peroxides contain from greater than about 1 to about 200 mmoltotal peroxide per kilogram of polymeric peroxide, more preferably fromabout 5 to about 100 mmol total peroxide per kilogram of polymericperoxide.

In one method for preparing the polymer peroxides, the olefin polymerstarting material is first exposed to high-energy ionizing radiationunder a blanket of inert gas, preferably nitrogen. The ionizingradiation should have sufficient energy to penetrate the mass of polymermaterial being irradiated to the extent desired. The ionizing radiationcan be of any kind, but preferably includes electrons and gamma rays.More preferred are electrons beamed from an electron generator having anaccelerating potential of about 500 to about 4,000 kilovolts.Satisfactory results are obtained at a dose of ionizing radiation ofabout 0.1 to about 15 megarads (“Mrad”), preferably about 0.5 to about9.0 Mrad.

The term “rad” is usually defined as that quantity of ionizing radiationthat results in the absorption of 100 ergs of energy per gram ofirradiated material regardless of the source of the radiation using theprocess described in U.S. Pat. No. 5,047,446. Energy absorption fromionizing radiation is measured by the well-known convention dosimeter, ameasuring device in which a strip of polymer film containing aradiation-sensitive dye is the energy absorption sensing means.Therefore, as used in this specification, the term “rad” means thatquantity of ionizing radiation resulting in the absorption of theequivalent of 100 ergs of energy per gram of the polymer film of adosimeter placed at the surface of the olefin material being irradiated,whether in the form of a bed or layer of particles, or a film, or asheet.

The irradiated olefin polymer material is then oxidized in a series ofsteps. The first treatment step consists of heating the irradiatedpolymer in the presence of a first controlled amount of active oxygengreater than about 0.004% by volume but less than about 15% by volume,preferably less than about 8% by volume, more preferably less than about5% by volume, and most preferably from about 1.3% to about 3.0% byvolume, to a first temperature of at least about 25° C. but below thesoftening point of the polymer, preferably about 25° C. to about 140°C., more preferably about 25° C. to about 100° C., and most preferablyabout 40° C. to about 80° C. Heating to the desired temperature isaccomplished as quickly as possible, preferably in less than about 10minutes. The polymer is then held at the selected temperature, typicallyfor about 5 to about 90 minutes, to increase the extent of reaction ofthe oxygen with the free radicals in the polymer. The holding time,which can be determined by one skilled in the art, depends upon theproperties of the starting material, the active oxygen concentrationused, the irradiation dose, and the temperature. The maximum time isdetermined by the physical constraints of the fluid bed.

In the second treatment step, the irradiated polymer is heated in thepresence of a second controlled amount of oxygen greater than about0.004% but less than about 15% by volume, preferably less than about 8%by volume, more preferably less than about 5% by volume, and mostpreferably from about 1.3% to about 3.0% by volume, to a secondtemperature of at least about 25° C. but below the softening point ofthe polymer. Preferably, the second temperature is from about 100° C. toless than the softening point of the polymer, and greater than the firsttemperature of the first step. The polymer is then held at the selectedtemperature and oxygen concentration conditions, typically for about 90minutes, to increase the rate of chain scission and to minimize therecombination of chain fragments so as to form long chain branches,i.e., to minimize the formation of long chain branches. The holding timeis determined by the same factors discussed in relation to the firsttreatment step.

In the optional third step, the oxidized olefin polymer material isheated under a blanket of inert gas, preferably nitrogen, to a thirdtemperature of at least about 80° C. but below the softening point ofthe polymer, and held at that temperature for about 10 to about 120minutes, preferably about 60 minutes. A more stable product is producedif this step is carried out. It is preferred to use this step if theirradiated, oxidized olefin polymer material is going to be storedrather than used immediately, or if the radiation dose that is used ison the high end of the range described above. The polymer is then cooledto a fourth temperature of about 70° C. over a period of about 10minutes under a blanket of inert gas, preferably nitrogen, before beingdischarged from the bed. In this manner, stable intermediates are formedthat can be stored at room temperature for long periods of time withoutfurther degradation.

A preferred method of carrying out the treatment is to pass theirradiated propylene polymer through a fluid bed assembly operating at afirst temperature in the presence of a first controlled amount ofoxygen, passing the polymer through a second fluid bed assemblyoperating at a second temperature in the presence of a second controlledamount of oxygen, and then maintaining the polymer at a thirdtemperature under a blanket of nitrogen, in a third fluid bed assembly.In commercial operation, a continuous process using separate fluid bedsfor the first two steps, and a purged, mixed bed for the third step ispreferred. However, the process can also be carried out in a batch modein one fluid bed, using a fluidizing gas stream heated to the desiredtemperature for each treatment step. Unlike some techniques, such asmelt extrusion methods, the fluidized bed method does not require theconversion of the irradiated polymer into the molten state andsubsequent re-solidification and comminution into the desired form. Thefluidizing medium can be, for example, nitrogen or any other gas that isinert with respect to the free radicals present, e.g., argon, krypton,and helium.

The concentration of peroxide groups formed on the polymer can becontrolled easily by varying the radiation dose during the preparationof the irradiated polymer and the amount of oxygen to which such polymeris exposed after irradiation. The oxygen level in the fluid bed gasstream is controlled by the addition of dried, filtered air at the inletto the fluid bed. Air must be constantly added to compensate for theoxygen consumed by the formation of peroxides in the polymer.

As used in this specification, the expression “room temperature” or“ambient” temperature means approximately 25° C. The expression “activeoxygen” means oxygen in a form that will react with the irradiatedolefin polymer material. It includes molecular oxygen, which is the formof oxygen normally found in air. The active oxygen content requirementof this invention can be achieved by replacing part or all of the air inthe environment by an inert gas such as, for example, nitrogen.

In another method for preparing the polymeric peroxides, an olefinpolymer starting material is treated with about 0.1 to about 4 wt % ofan organic peroxide initiator while adding a controlled amount of activeoxygen so that the olefin polymer material is exposed to greater thanabout 0.004% by volume, but less than about 15% by volume of activeoxygen, preferably less than about 8%, more preferably less than about5% by volume, and most preferably about 1.3% to about 3% by volume, at atemperature of at least about 25° C. but below the softening point ofthe polymer, preferably about 25° C. to about 140° C. In a second step,the polymer is then heated to a temperature of at least about 25° C. upto the softening point of the polymer (140° C. for a propylenehomopolymer), preferably from about 100° C. to less than the softeningpoint of the polymer, at an oxygen concentration that is within the samerange as in the first treatment step. The total reaction time istypically up to three hours. After the oxygen treatment, the polymer istreated at a temperature of at least about 80° C. but below thesoftening point of the polymer, typically for one hour, in an inertatmosphere such as nitrogen to quench any active free radicals.

Suitable organic peroxides include acyl peroxides, such as benzoyl anddibenzoyl peroxides; dialkyl and aralkyl peroxides, such asdi-tert-butyl peroxide, dicumyl peroxide; cumyl butyl peroxide;1,1,-di-tert-butylperoxy-3,4,4-trimethylcyclohexane;2,5-dimethyl-1,2,5-tri-tert-butylperoxyhexane, andbis(alpha-tert-butylperoxy isopropylbenzene), and peroxy esters such asbis(alpha-tert-butylperoxy pivalate; tertbutylperbenzoate;2,5-dimethylhexyl-2,5-di(perbenzoate); tert-butyl-di(perphthalate);tert-butylperoxy-2-ethylhexanoate, and1,1-dimethyl-3-hydroxybutylperoxy-2-ethyl hexanoate, andperoxycarbonates such as di(2-ethylhexyl) peroxy dicarbonate,di(n-propyl)peroxy dicarbonate, and di(4-tert-butylcyclohexyl)peroxydicarbonate. The peroxides can be used neat or in diluent medium, havingan active concentration of from about 0.1 to about 6.0 parts per hundred(“pph”), preferably from about 0.2 to about 3.0 pph. Particularlypreferred is tert-butyl peroctoate as a 50 weight % dispersion inmineral oil, sold commercially under the brand name of Lupersol PMS.

The polymeric peroxides contain peroxide linkages that degrade duringcompounding to form various oxygen-containing polar functional groups,e.g., carboxylic acids, ketones, esters and lactones. In addition, thenumber average and weight average molecular weight of the polymericperoxide is usually much lower than that of the corresponding olefinpolymer used to prepare same, due to the chain scission reactions duringirradiation and oxidation.

Preferably, the number average molecular weight and weight averagemolecular weight of the polymeric peroxide is greater than 10,000. Atnumber average and weight average molecular weight values lower than10,000, the compatibilizing dispersant will “bloom” at the surface ofthe finished product.

Preferably, the starting material for preparing the polymeric peroxidecompatiblizing dispersant is a propylene polymer material. Morepreferably, the starting material is a propylene homopolymer having anisotactic index greater than about 80%. The polymeric peroxide ispreferably prepared by irradiation followed by exposure to oxygen asdescribed herein above.

Ionomers of the polymeric peroxides can be prepared by methods wellknown in the art, where at least some of the carboxylic acid groups inthe polymeric peroxides are neutralized in a slurry process, a meltprocess, by reactive extrusion, or by grafting with monomer salts. Meltneutralization is preferred. The basic compounds used for neutralizationcan be oxides, hydroxides, and salts of metals of Groups IA, IIA, andIIB of the Periodic Table. These compounds include, for example, sodiumhydroxide, potassium hydroxide, zinc oxide, sodium carbonate, potassiumcarbonate, lithium hydroxide, sodium bicarbonate, potassiumhydrocarbonate, and lithium carbonate. The Na ionomer of the polymericperoxide is preferred.

Grafts of the polymeric peroxides can be prepared via reaction of thepolymeric peroxides with monomers, by methods well known in the art. Forexample, U.S. Pat. No. 5,817,707 describes a process for makingpropylene graft copolymers using a redox initiator system. Suitablemonomers include any monomeric vinyl compound wherein the vinyl radical,CH₂═CHR—, in which R is H or methyl, is attached to a straight orbranched aliphatic chain having 2-12 carbon atoms or to a substituted orunsubstituted aromatic compound having 6-20 carbon atoms, heterocycliccompound having 4-20 carbon atoms, or alicyclic ring compound having3-20 carbon atoms in a mono or polycyclic compound. Typical substituentgroups can be C₁₋₁₀ straight or branched alkyl, C₁₋₁₀ straight orbranched hydroxyalkyl, C₆₋₁₄ aryl, and halo, such as fluorine, chlorine,bromine or iodine. Preferably, the vinyl monomer can be acrylic acid,methacrylic acid, maleic acid, maleic anhydride, vinyl-substitutedaromatic compounds having 6-20 carbon atoms, vinyl-substitutedheterocyclic compounds having 4-20 carbon atoms, or vinyl-substitutedalicyclic compounds having 3-20 carbon atoms. Preferred vinyl monomersinclude styrene, vinylnaphthalene, vinylpyridine, vinylpyrrolidone,vinylcarbazole, methylstyrenes, methylchlorosyrene,p-teret-butylstyrene, methylvinylpyridine, and ethylvinylpyridine, and(meth)acrylic nitriles and (meth)acrylic acid esters such asacrylonitrile, methacrylonitrile, acrylate esters, such as the methyl,ethyl, hydroxyethyl, 2-ethylhexyl, and butyl acrylate esters, andmethacrylate esters, such as the methyl, ethyl, butyl, benzyl,phenylethyl, phenoxyethyl, epoxypropyl, and hydroxypropyl methacrylateesters, and mixtures thereof. Polymeric peroxide compounds grafted withacrylic acid are preferred.

The compatibilizing dispersants are present in an amount from about 5 toabout 20 wt % based on the total weight of the composition. Preferably,the compatibilizing dispersants are present in an amount from about 7 toabout 15 wt %, more preferably from about 8 to about 12 wt %.

The smectite clay, olefin polymer material and compatibilizingdispersant can be combined at ambient temperature in conventionaloperations well known in the art; including, for example, drum tumbling,blending, or with low or high speed mixers. The resulting composition isthen compounded in the molten state in any conventional manner wellknown in the art, in batch or continuous mode; for example, by using aBanbury mixer, a kneading machine, or a single or twin screw extruder.The material can then be pelletized.

The nanocomposite compositions of the invention can be used to makearticles of manufacture by conventional shaping processes such as meltspinning, casting, vacuum molding, sheet molding, injection molding andextruding. Examples of such articles are components for technicalequipment, household equipment, sports equipment, bottles, containers,components for the electrical and electronics industries, automobilecomponents and fibers. They are especially useful for the fabrication ofextruded films and film laminates, for example, films for use in foodpackaging.

Unless otherwise specified, the properties of the olefin polymermaterials, and compositions that are set forth in the following exampleshave been determined according to the test methods set forth in Table Ibelow. TABLE I Melt Flow Rate (“MFR”) ASTM D1238, units of dg/minPropylene polymer material: (230° C.; 2.16 kg) Ethylene polymermaterial: (190° C.; 2.16 kg) Butene-1 polymer material: (230° C.; 2.16kg) Isotactic Index, (“I.I.”) Defined as the percent of olefin polymerinsoluble in xylene. The weight percent of olefin polymer soluble inxylene at room temperature is determined by dissolving 2.5 g of polymerin 250 ml of xylene at room temperature in a vessel equipped with astirrer, and heating at 135° C. with agitation for 20 minutes. Thesolution is cooled to 25° C. while continuing the agitation, and thenleft to stand without agitation for 30 minutes so that the solids cansettle. The solids are filtered with filter paper, the remainingsolution is evaporated by treating it with a nitrogen stream, and thesolid residue is vacuum dried at 80° C. until a constant weight isreached. These values correspond substantially to the isotactic indexdetermined by extracting with boiling n-heptane, which by definitionconstitutes the isotactic index of polypropylene. Tensile strength @yield ASTM D638-89 Flex Modulus ASTM D790-92 Flex strength @ yield ASTMD790-92 Heat Distortion ASTM D648-01B Temperature, (“HDT”) @ 1.82 MPaHeat Distortion ASTM D648-01B Temperature @ 0.46 MPa Notched Izod Impactat ASTM-D256-Procedure A 23° C. Elongation @ Yield ASTM D638-89Elongation @ Break ASTM D638-89 Peroxide Concentration QuantitativeOrganic Analysis via Functional Groups, by S. Siggia et al., 4^(th) Ed.,NY, Wiley 1979, pp. 334-42

Unless otherwise specified, all references to parts, percentages andratios in this specification refer to percentages by weight.

EXAMPLE 1

This example illustrated the preparation of a polymeric peroxide.

A propylene homopolymer having an MFR of 0.32 dg/min and I.I. of 95.6%commercially available from Basell USA Inc. was irradiated at 0.5 Mradunder a blanket of nitrogen. The irradiated polymer was then treatedwith 1.35% by volume of oxygen at 80° C. for 5 minutes and then with1.35% by volume of oxygen at 140° C. for an additional 60 minutes. Theoxygen was then removed. The polymer was then heated at 140° C. under ablanket of nitrogen for 60 minutes, cooled and collected. The MFR of theresultant polymeric peroxide was 350 dg/min. The peroxide concentrationwas 9.1 mmole/kg of polymer.

EXAMPLE 2

This example illustrated the preparation of a polymeric peroxide.

The propylene homopolymer of Example 1 was irradiated according to theprocedure of Example 1 and then treated with 1.75% by volume of oxygenat 80° C. for 5 minutes and then with 1.75% by volume of oxygen at 130°C. for another 60 minutes. The oxygen was then removed. The polymer wasthen heated at 140° C. under a blanket of nitrogen for 60 minutes,cooled and collected. The MFR of the resultant polymeric peroxide was1200 dg/min. The peroxide concentration was 17.1 mmole/kg of polymer.

EXAMPLE 3

This example illustrated the preparation of an acrylic acid graftedpolymeric peroxide.

The polymeric peroxide of Example 2 was heated in a reactor to 140° C.in an inert atmosphere. Acrylic acid (15 pph) was added to the reactorat the rate 1 pph/min. After monomer addition, the polymer was heated at140° C. for another 90 minutes. The reactor vent was then opened. Astream of nitrogen was introduced to the reactor to remove any unreactedmonomer. After 30 minutes at 140° C., the polymer was cooled andcollected. The resulting grafted polymer had an MFR of 1200 dg/nin.

EXAMPLE 4

This example illustrated the preparation of an ionomer of a polymericperoxide.

A Na⁺ ionomer of the polymeric peroxide of Example 1 was prepared byneutralization using reactive extrusion in a co-rotating intermeshingLeistritz LSM 34GL twin screw extruder (8 zone plus a die, L/D˜30) witha 3VM screw, commercially available from American Leistritz ExtruderCorp., USA. Sodium carbonate salt was used as a base (1 part per hundredparts of the polymer composition). The extrusion conditions were 250 rpmwith a throughput of 11.34 kg/hr, using vacuum to remove anyby-products. The resultant ionomer had an MFR of 347 dg/min.

EXAMPLES 6-7, 9-12, 14-16 AND COMPARATIVE EXAMPLES 5, 8 AND 13

In the following Tables and Examples, the following components wereused:

Epolene E43: polypropylene grafted with maleic anhydride, commerciallyavailable from Eastman Kodak, having an acid number of 40, withapproximately 4.5 wt % of total maleic anhydride (“PP-g-MA”).

Clay A: Cloisite 20-montmorillonite clay, commercially available fromSouthern Clay Products, containing 38 wt % dimethyl, dehydrogenatedtallow quaternary ammonium intercalant. The quaternary ammoniumconcentration is 95 meq/100 g and the basal clay spacing is 24 angstrom(2.4 nm).

Clay B was prepared by suspending 30 g of Montmorillonite K10 clay,commercially available from Aldrich Chemical Company, in 200 ml ofdeionized water and heating to 60° C. In a separate beaker, 15 g ofpolypropylene glycol)bis(2-aminopropyl ether) were dissolved in 100 mlof water and heated to 70-75° C. 37% HCl (12 g) was added slowly whilestirring. After two hours, the solution was poured into the claysuspension maintained at 60° C. and stirred for two hours at thattemperature. The resulting clay was filtered, washed neutral, air dried,and finally dried at 60° C. under vacuum. The final weight was 38 g.Intercalation of the silicate layers of the clay with the organicswelling agent took place by absorption.

All materials, including the clay, were simultaneously dry-blended andbag mixed with stabilizer package, FS210, before extrusion. FS210 is a1/1 ratio of FS042 alkyl alkoxy amine and Chimassorb 119 hindered aminelight stabilizer, both of which are commercially available from CibaChemical Specialties Company. Compounding was performed in a co-rotatingintermeshing Leistritz LSM 34 GL twin-screw extruder, commerciallyavailable from American Leistritz Extruder Corp., USA. Extrusiontemperatures were 190° C. for all zones. The actual melt temperature wasapproximately 180-190° C., with a throughput of 9.1 kg/hr. and screwspeed of 200 rpm. Full vacuum was used to remove the volatile organicmaterial from the clay. All materials were injection molded on a 5 oz.Battenfeld injection molding machine available from Battenfeld, Austria,using a melt temperature of 200° C. and mold temperature of 60° C. Theinjection speed was 2.0 cm/min.

Comparative Example 5 and Examples 6-7 demonstrate the use of apropylene polymeric peroxide compatibilizing dispersant in nanocompositecompositions containing montmorillonite clay and propylene homopolymerscommercially available from Basell USA Inc. The composition and physicalproperties of Comparative Example 5 and Examples 6-7 are set forth inTable II. TABLE II Comp. Ex. 5 Ex. 6 Ex. 7 Propylene homopolymer, MFR =4, 96.8 91.8 86.8 I.I. = 95%, wt % Polymeric Peroxide of Example 1, 5.010.0 wt % Clay A, wt % 3.0 3.0 3.0 Propylene homopolymer, MFR = 400,I.I. = 97.5%, wt % FS210, wt % 0.2 0.2 0.2 Physical Properties NotchedIzod Impact @ 23° C., 0.37 0.37 0.43 J/cm Tensile Strength @ yield, MPa35.65 34.97 36.36 Elongation @ yield, % 10 10 9 Elongation @ break, % 7165 74 Flexural Strength @ yield, MPa 44.48 44.14 46.67 Flexural Modulus,1% secant, MPa 1428 1448 1531 HDT @ 1.82 MPa, ° C. 56 56 58 HDT @ 0.46MPa, ° C. 93 100 110 MFR@ 230° C., 3.8 kg., dg/min 12 14 16

As is evident from the data in Table II, nanocomposite compositionscontaining the polymeric peroxide compatibilizing dispersants exhibitimproved physical properties, as demonstrated by the higher flexuralmodulus and equivalent to better heat deflection properties in Example6, and higher tensile strength, elongation at break, flexural strengthand modulus and improved heat deflection properties in Example 7 ascompared to the control composition without the polymeric peroxide.

Comparative Example 8 and Examples 9-12 demonstrate the use of apropylene polymeric peroxide compatibilizing dispersant in nanocompositecompositions containing montmorillonite clay and a propylene homopolymercommercially available from Basell USA Inc. The compositions andphysical properties of Comparative Example 8 and Examples 9-12 are setforth in Table III. TABLE III Comp. Ex. 8 Ex. 9 Ex. 10 Ex. 11 Ex. 12Propylene homopolymer, 96.8 86.8 86.8 86.8 86.8 MFR = 4, I.I. = 95%, wt% PP-g-MA, wt % 5.0 Polymeric Peroxide of Example 1, wt % 10.0 5.0Acrylic Acid grafted polymeric 10.0 peroxide of Example 3, wt % Na⁺ionomer of polymeric 10.0 peroxide of Example 4, wt % Clay A, wt % 3.03.0 3.0 3.0 3.0 FS210, wt % 0.2 0.2 0.2 0.2 0.2 Physical PropertiesNotched Izod Impact @ 23° C., J/cm 0.37 0.43 0.37 0.37 0.27 TensileStrength @ yield, MPa 35.65 36.36 35.81 35.54 35.87 Elongation @ yield,% 10 9 9 9 9 Elongation @ break, % 71 74 29 62 102 Flexural Strength @yield, MPa 44.48 46.67 49.43 48.78 46.89 Flexural Modulus, 1% secant,MPa 1428 1531 1586 1552 1552 HDT @ 1.82 MPa, ° C. 56 58 60 56 59 HDT @0.46 MPa, ° C. 93 110 109 106 97 MFR@ 230° C., 3.8 kg., dg/min 12 16 1517

As is evident from the data in Table III, nanocomposite compositionscontaining 10 wt % of the polymeric peroxide compatibilizing dispersant,the acrylic acid grafted polymeric peroxide compatibilizing dispersant,and the 5 wt %/5 wt % blend of the polymeric peroxide compatibilizingdispersant and maleic anhydride grafted polypropylene, demonstrate animproved balance of properties relative to Comparative Example 8 thatdoes not contain a polymeric peroxide compatibilizing dispersant. TheNa⁺ ionomer polymeric peroxide compatibilizing dispersant demonstratesimproved flexural strength, flexural modulus, and equivalent or betterheat deflection temperatures relative Comparative Example 8.

Comparative Example 13 and Examples 14-16 demonstrate the use of apropylene polymeric peroxide, ionomer of a propylene polymer peroxideand acrylic acid grafted propylene polymeric peroxide compatibilizingdispersant in nanocomposite compositions containing montmorillonite clayand propylene homopolymers commercially available from Basell USA Inc.The compositions and physical properties of Comparative Example 13 andExamples 14-16 are set forth in Table IV. TABLE IV Comp. Ex. 13 Ex. 14Ex. 15 Ex. 16 Propylene homopolymer, MFR = 96.8 86.8 86.8 86.8 4, I.I. =95.0%, wt % Polymeric Peroxide of Example 1, 10.0 wt % Acrylic Acidgrafted polymeric 10.0 peroxide of Example 3, wt % Na⁺ ionomer ofpolymeric 10.0 peroxide of Example 4, wt % Clay B, wt % 3.0 3.0 3.0 3.0FS210, wt % 0.2 0.2 0.2 Physical Properties Notched Izod Impact @ 23°C., 0.37 0.32 0.32 0.37 J/cm Tensile Strength @ yield, MPa 33.74 33.2233.93 35.92 Elongation @ yield, % 11 44 11 9 Elongation @ break, % 193162 115 39 Flexural Strength @ yield, MPa 42.33 42.94 44.21 48.85Flexural Modulus, 1% secant, MPa 1310 1324 1359 1531 HDT @ 1.82 MPa, °C. 55 54 56 55 HDT @ 0.46 MPa, ° C. 92 88 94 96 MFR@ 230° C., 3.8 kg.,dg/min 12 18 16

As is evident from the data in Table IV, the composition containing 10wt % of the polymeric peroxide compatibilizing dispersant demonstratesimproved elongation at yield, flexural strength, and flexural modulusrelative to Comparative Example 13 that does not contain acompatibilizing dispersant. The composition containing 10 wt % of theNa⁺ ionomer of the polymeric peroxide demonstrates improved tensilestrength, flexural strength, flexural modulus, and equivalent or betterheat deflection properties relative to Comparative Example 13 that doesnot contain a compatibilizing dispersant. The composition containing 10wt % of the acrylic acid grafted polymeric peroxide demonstratesimproved tensile strength, flexural strength and modulus, and equal toimproved heat deflection properties, relative to Comparative Example 13that does not contain a compatibilizing dispersant.

Transmitted light microscopy was performed on microtomed sections cutfrom injection-molded tensile bar samples, to evaluate clay dispersionin nanocomposite compositions. Transmitted light microscopy photographsof propylene polymer nanocomposite compositions, taken with an opticalmicroscope commercially available from Leitz Aristomet, are shown inFIGS. 1-2. These figures demonstrate that propylene polymernanocomposite compositions containing polymeric peroxide compatibilizingdispersants (FIG. 2, Example 7) enhanced clay dispersion as compared toa propylene polymer nanocomposite composition without any compatibilizeror dispersant (FIG. 1, Comparative Example 5).

Cross-polarized light images were taken of microtomed sections cut fromtensile bar samples to evaluate crystalline morphology, as shown inFIGS. 3-4. The cross-polarized photographs were taken with an opticalmicroscope commercially available from Leitz Aristomet. The Figuresdemonstrate that the combination of smectite clay and compatibilizingdispersants serve as a mild nucleating agent for propylene polymermaterial, as shown by the reduction in spherulite size (FIG. 4, Example7), relative to Comparative Example 5 (FIG. 3).

Conventional differential scanning calorimeter (“DSC”) scans wereconducted on specimens cut from injection-molded tensile bars toevaluate crystallization temperatures using a DSC 2920 differentialscanning calorimeter commercially available from TA Instruments. Thetemperature scan range was set between 25 and 235° C., and the scan ratewas 20° C./min. The DSC scans are shown in FIG. 5 for nanocompositecompositions containing the polymeric peroxide compatibilizingdispersant of Example 7 (curve 1), and the polymeric peroxide/maleatedpropylene polymer mixture of Example 12 (curve 3), relative to thecomposition containing no maleated propylene polymer material orpolymeric peroxide of Comparative Example 5 (curve 2). FIG. 5demonstrates differences in the cooling scans for the compositioncurves. The crystallization peak temperature in the cooling scan variedfrom 120° C. for Example 7 (curve 1), to 117° C. for Comparative Example5 (curve 2) and 110° C. for Example 12 (curve 3). These results confirmthe observations from the cross-polarized light images, that thecombination of the compatibilizing dispersants and smectite clay enhancethe nucleation of the propylene polymer material, while the use ofmaleated propylene polymer material suppresses the nucleation of thepropylene polymer material.

Other features, advantages and embodiments of the invention disclosedherein will be readily apparent to those exercising ordinary skill afterreading the foregoing disclosures. In this regard, while specificembodiments of the invention have been described in considerable detail,variations and modifications of these embodiments can be effectedwithout departing from the spirit and scope of the invention asdescribed and claimed.

1. A polyolefin nanocomposite composition comprising: A. 5 to 20 wt % ofa compatibilizing dispersant chosen from an olefin polymer peroxide, anionomer of an olefin polymer peroxide, a grafted olefin polymerperoxide, and mixtures thereof; B. 1 to 15 wt % of a smectite clay; andC. 65 to 94 wt % of an olefin polymer material; wherein the sum ofcomponents A+B+C is equal to 100 wt %.
 2. The composition of claim 1comprising A. 7 to 15 wt % of the compatibilizing dispersant; B. 2 to 10wt % of the smectite clay; and C. 75 to 91 wt % of the olefin polymermaterial.
 3. The composition of claim 1 wherein a starting material forpreparing the compatibilizing dispersant A is chosen from propylenepolymers, ethylene polymers, butene-1 polymers and mixtures thereof. 4.The composition of claim 1 wherein the olefin polymer material C ischosen from propylene polymers, ethylene polymers, butene-1 polymers andmixtures thereof.
 5. The composition of claim 3, wherein the propylenepolymers are chosen from: (a) a homopolymer of propylene having anisotactic index greater than 80%; (b) a random copolymer of propyleneand an olefin chosen from ethylene and C₄-C₁₀ α-olefins, containing 1 to30 wt % of the olefin, and having an isotactic index greater than 60%;(c) a random terpolymer of propylene and two olefins chosen fromethylene and C₄-C₈ α-olefins, containing 1 to 30 wt % of the olefins,and having an isotactic index greater than 60%; (d) an olefin polymercomposition comprising: (i) 10 parts to 60 parts by weight of apropylene homopolymer having an isotactic index of at least 80%, or acrystalline copolymer chosen from (a) propylene and ethylene, (b)propylene, ethylene and a C₄-C₈ α-olefin, and (c) propylene and a C₄-C₈α-olefin, the copolymer having a propylene content of more than 85% byweight, and an isotactic index greater than 60%; (ii) 3 parts to 25parts by weight of a copolymer of ethylene and propylene or a C₄-C₈α-olefin that is insoluble in xylene at ambient temperature; and (iii)10 parts to 80 parts by weight of an elastomeric copolymer chosen from(a) ethylene and propylene, (b) ethylene, propylene, and a C₄-C₈α-olefin, and (c) ethylene and a C₄-C₈ α-olefin, the copolymeroptionally containing from 0.5% to 10% by weight of a diene, andcontaining less than 70% by weight of ethylene, and being soluble inxylene at ambient temperature and having an intrinsic viscosity of 1.5to 4.0 dl/g; the total of (ii) and (iii), based on the total olefinpolymer composition being from 50% to 90%, and the weight ratio of(ii)/(iii) being less than 0.4, wherein the composition is prepared bypolymerization in at least two stages; (e) a thermoplastic olefincomprising: (i) 10% to 60% of a propylene homopolymer having anisotactic index of at least 80%, or a crystalline copolymer chosen from(a) ethylene and propylene, (b) ethylene, propylene and a C₄-C₈α-olefin, and (c) ethylene and a C₄-C₈ α-olefin, the copolymer having apropylene content greater than 85% and an isotactic index of greaterthan 60%; (ii) 20% to 60% of an amorphous copolymer chosen from (a)ethylene and propylene, (b) ethylene, propylene, and a C₄-C₈ α-olefin,and (c) ethylene and a α-olefin, the copolymer optionally containingfrom 0.5% to 10% of a diene, and containing less than 70% ethylene andbeing soluble in xylene at ambient temperature; and (iii) 3% to 40% of acopolymer of ethylene and propylene or an α-olefin that is insoluble inxylene at ambient temperature; and (f) mixtures thereof.
 6. Thecomposition of claim 4, wherein the propylene polymers are chosen from:(a) a homopolymer of propylene having an isotactic index greater than80%; (b) a random copolymer of propylene and an olefin chosen fromethylene and C₄-C₁₀ α-olefins, containing 1 to 30 wt % of the olefin,and having an isotactic index greater than 60%; (c) a random terpolymerof propylene and two olefins chosen from ethylene and C₄-C₈ α-olefins,containing 1 to 30 wt % of the olefins, and having an isotactic indexgreater than 60%; (d) an olefin polymer composition comprising: (i) 10parts to 60 parts by weight of a propylene homopolymer having anisotactic index of at least 80%, or a crystalline copolymer chosen from(a) propylene and ethylene, (b) propylene, ethylene and a C₄-C₈α-olefin, and (c) propylene and a C₄-C₈ α-olefin, the copolymer having apropylene content of more than 85% by weight, and an isotactic indexgreater than 60%; (ii) 3 parts to 25 parts by weight of a copolymer ofethylene and propylene or a C₄-C₈ α-olefin that is insoluble in xyleneat ambient temperature; and (iii) 10 parts to 80 parts by weight of anelastomeric copolymer chosen from (a) ethylene and propylene, (b)ethylene, propylene, and a C₄-C₈ α-olefin, and (c) ethylene and a C₄-C₈α-olefin, the copolymer optionally containing from 0.5% to 10% by weightof a diene, and containing less than 70% by weight of ethylene, andbeing soluble in xylene at ambient temperature and having an intrinsicviscosity of 1.5 to 4.0 dl/g; the total of (ii) and (iii), based on thetotal olefin polymer composition being from 50% to 90%, and the weightratio of (ii)/(iii) being less than 0.4, wherein the composition isprepared by polymerization in at least two stages; (e) a thermoplasticolefin comprising: (i) 10% to 60% of a propylene homopolymer having anisotactic index of at least 80%, or a crystalline copolymer chosen from(a) ethylene and propylene, (b) ethylene, propylene and a C₄-C₈α-olefin, and (c) ethylene and a C₄-C₈ α-olefin, the copolymer having apropylene content greater than 85% and an isotactic index of greaterthan 60%; (ii) 20% to 60% of an amorphous copolymer chosen from (a)ethylene and propylene, (b) ethylene, propylene, and a C₄-C₈ α-olefin,and (c) ethylene and a α-olefin, the copolymer optionally containingfrom 0.5% to 10% of a diene, and containing less than 70% ethylene andbeing soluble in xylene at ambient temperature; and (iii)₃% to 40% of acopolymer of ethylene and propylene or an α-olefin that is insoluble inxylene at ambient temperature; and (f) mixtures thereof.
 7. Thecomposition of claim 3, wherein the ethylene polymers are chosen from:(a) homopolymers of ethylene; (b) random copolymers of ethylene and analpha-olefin chosen from C₃₋₁₀ alpha-olefins; (c) random terpolymers ofethylene and C₃₋₁₀ alpha-olefins; and (d) mixtures thereof.
 8. Thecomposition of claim 4, wherein the ethylene polymers are chosen from:(a) homopolymers of ethylene; (b) random copolymers of ethylene and analpha-olefin chosen from C₃₋₁₀ alpha-olefins; (c) random terpolymers ofethylene and C₃₋₁₀ alpha-olefins; and (e) mixtures thereof.
 9. Thecomposition of claim 3, wherein the butene-1 polymers are chosen from:(a) homopolymers of butene-1; (b) copolymers or terpolymers of butene-1with a non-butene alpha-olefin comonomer content from 1 to 15 mole %;and (c) mixtures thereof.
 10. The composition of claim 4, wherein thebutene-1 polymers are chosen from: (a) homopolymers of butene-1; (b)copolymers or terpolymers of butene-1 with a non-butene alpha-olefincomonomer content from 1 to 15 mole %; and (c) mixtures thereof.
 11. Thecomposition of claim 1 wherein the smectite clay B is chosen frommontmorillonite, nontronite, beidellite, volkonskoite, hectorite,saponite, sauconite, sobockite, stevensite, svinfordite and mixturesthereof.
 12. The composition of claim 11 wherein the smectite clay B ismontmorillonite.
 13. The composition of claim 1 wherein thecompatibilizing dispersant A is an olefin polymer peroxide containinggreater than 1 mmol total peroxide per kilogram of the olefin polymerperoxide.
 14. The composition of claim 1 wherein the compatibilizingdispersant A is a sodium ionomer of an olefin polymer peroxide.
 15. Thecomposition of claim 1 wherein the compatibilizing dispersant A is agrafted olefin polymer peroxide.
 16. The composition of claim 15 whereinthe grafted olefin polymer peroxide is grafted with a monomeric vinylcompound wherein a vinyl radical, CH₂═CHR—, in which R is H or methyl,is attached to a straight or branched aliphatic chain having 2-12 carbonatoms or to a substituted or unsubstituted aromatic compound having 6-20carbon atoms, heterocyclic compound having 4-20 carbon atoms, oralicyclic ring compound having 3-20 carbon atoms in a mono or polycycliccompound.
 17. The composition of claim 16 wherein the monomeric vinylcompound is chosen from acrylic acid, methacrylic acid, maleic acid,maleic anhydride, vinyl-substituted aromatic compound having 6-20 carbonatoms, vinyl-substituted heterocyclic compound having 4-20 carbon atoms,vinyl-substituted alicyclic compound having 3-20 carbon atoms andmixtures thereof.
 18. The composition of claim 17 wherein the monomericvinyl compound is acrylic acid.
 19. The composition of claim 1 whereinthe smectite clay B is treated with a quaternary ammonium salt.
 20. Ashaped article comprising the composition of claim 1.